The emergence of multimedia computing is driving a need for digitally transmitting and receiving high quality motion video. The high quality motion video consists of high resolution images, each of which requires a large amount of space in a system memory or on a data storage device. Additionally, about 30 of these high resolution images need to be processed and displayed per second in order for a viewer to experience an illusion of motion. As a transfer of large, uncompressed streams of video data is time consuming and costly, data compression is typically used to reduce the amount of data transferred per image.
In motion video, much of the image data remains constant from one frame to another frame. Therefore, video data may be compressed by first describing a reference frame and then describing subsequent frames in terms of changes from the reference frame. Standards from an organization called Motion Pictures Experts Group (MPEG) have evolved to support high quality, full motion video. One primary operation performed in MPEG is block matching. A motion vector describing the offset between the current frame and a best match block is then computed. The motion vector is subsequently sent back to a host processor. Through the motion vector, MPEG allows a plurality of images to be compressed, along with code for performing a decompression.
In this light, the decompression process is analogous to an operation known as morphing. The morphing operation changes one picture into another by creating a smooth transitional link between the two pictures. The process preserves features associated with each image by mapping the features from a source image to corresponding features in a destination image. In one version of the conventional morphing process, given two pictures and correspondences between them, the morphing process produces a movie using the two pictures. Further, in a copending application, filed by Todor Georgiev on Apr. 17, 1998 and entitled "MULTI-IMAGE MORPHING", hereby incorporated by reference, multiple images may be morphed together to create a plurality of morphing movies.